The first couplet of the key in Orth & Moore uses to the distinctive "cowlick" pubescence of the abdominal tergites in the two species C. seminitens and C. canescens to separate them out from the remaining eight species. The detail view here shows this "cowlick" pubescence.

The second couplet states that C. seminitens can be distinguished by its having denser pubescence on the last two sternites than on the preceding sternites. Note that sternites can't be seen in my dorsal image here. Nevertheless, in their detailed descriptions for seminitens and canescens, Orth & Moore emphasize another distinctive character difference. Namely, the first few tergites of seminitens have "wavy" acrocostal sutures, whereas those of canescens have straight acrocostal sutures. I'd say the the first few acrocostal sutures are wavy here. This is consistent with the top two figures in Orth & Moore, showing seminitens on the left and canescens on the right. [Note: I couldn't find a definition of "acrocostal sutures", but I presume the term refers to the posterior edges of the tergites..."acro" = top, and "costal" = rib.]

In meticulously comparing the very detailed description of C. seminitens in Orth & Moore line-by-line with the specimen in my photos, I was delighted to see how seamlessly it seemed to fit...until I got to "Apical margin of 6th sternite with a triangular emargination as deep as wide". At that point I thought, "Uh oh...there's no notch at the end of the 6th sternite in my photo." But then, reading a few sentences further, the authors clearly state that it's just males that have such a notch...whereas females have "Apical margin of 6th sternite entire." Thus, I thought all was well...and concluded this is a female. Only later did I realize (thanks to v. belov's comment below) that I had been inadvertently misreading sternite as tergite the whole time! Thus, since my dorsal image only shows tergites...and I don't have a ventral image...these points were moot. (And now you see the reason for all the somewhat distracting use of bold emphasis above!)


[Note: The tip of the 6th tergite in the drawing of seminitens in Orth & Moore is shown as notched, whereas it's entire on the beetle imaged here. I'm speculating that the notching of the 6th tergite might match with the notching of the 6th sternite, which is given as a character for the male of seminitens. If so, as the tip of the 6th tergite here is entire, perhaps that indicates is a female.]